Field of the Invention
The present invention relates attachment hardware for modular insulation systems and more particularly to a modular ceramic fiber system in which the ceramic fiber insulation module may be readily installed by fastening through its hot face.
Modular insulation systems for furnaces kilns and the like are not of themselves novel A wide variety of modular systems have been proposed or employed which include as a part thereof modules formed in part of ceramic fiber blanket or mat. Many of these have enjoyed great commercial success. However, there remains a need for a ceramic fiber modular insulation system which can be easily and rapidly installed by a labor force not having highly specialized skills There further remains a need for a ceramic fiber modular insulation system in which the modules can be secured in a variety of ways according to service conditions intended and equipment available for use in effecting installation. For example, in some installations it is adequate and expedient to simply affix the modules with self tapping screws or bolts inserted into the module from its hot face. In others welding through the module is required and yet others it is desired to place the module onto the previously installed threaded studs or other support hardware previously affixed to the furnace wall. It is desired to meet these objectives in as economical manner as possible and without need of a variety of modules each designed for a particular method of attachment.
Examples of known modular ceramic fiber insulation systems include the following:
U.S. Pat. No. 3,940,244 to Sauder et al discloses an insulation module formed of a plurality of strips of resilient fiber insulation positioned adjacent each other in side-by-side relation in which the module includes a backing sheet of material such as expanded metal having openings throughout which engage with a configured arcuate washer and stud to retain the module securely to the furnace wall These modules may also be attached by a stud welding technique more fully described in U.S. Pat. No. 3,706,870 to Sauder et al, or an explosive impact type dry pin fastener.
U.S. Pat. No. 3,832,815 to Balaz et al. discloses modular ceramic fiber insulation in which each module is fabricated of layers of high temperature ceramic fiber blanket disposed substantially perpendicular to the hot face of the furnace lining. The layers are compressed during assembly into a resilient bundle The layers are retained in modular form by pins threaded substantially perpendicularly through the blanket layers and disposed near the outer cold face of the module that is remote from the interior of the furnace. The ends of these pins extend through L-shaped elongated strips of expanded metal having a length corresponding to the width of the assembled strips. The retainer members are secured to the furnace wall by, for example, a plurality of pins which extend through the furnace shell.
U.S. Pat. No. 3,952,470 to Byrd, Jr. discloses modular ceramic fiber insulation wherein a folded insulating blanket of refractory fibrous material is provided with a support beam mounted lengthwise and embedded within a fold in the blanket to support the blanket, and a mounting means which includes suspension arm which extends through the folds of the blanket from the support beam to an attachment beam for mounting with the wall of the furnace The attachment beam has openings formed therein for passage of connecting members therethrough to attach the attachment beam to the wall of the furnace. The main support beam is attached to the furnace wall in conventional manner, i.e. by welding or the use of screws, bolts and the like.
U.S. Pat. No. 4,339,902 to Cimochowski et al. discloses a modular thermal insulation formed of folded fibrous insulating blanket and a metallic attachment structure adapted to be secured to a wall of a furnace or the like. A bar is embedded in a fold of the blanket. The bar is attached by a connector to the main beam in the form of a C-shaped channel which is mounted to the furnace wall by first placing a flanged mounting clip against the furnace wall and thereafter sliding the C-shaped attachment means over the clip so that the flanges of the beam engage the flanges of the mounting clip.
U.S. Pat. No. 4,381,634 and 4,449,345 to Hounsel et al. discloses the refractory ceramic fiber blanket module having a continuous strip of ceramic fiber folded into a number of layers in serpentine fashion and retained in modular configuration by attachment hardware adapted for mounting on one surface of a furnace. Certain of the folds contains support rods which engage a perpendicularly extending support rod which penetrates a plurality of the layers of blanket adjacent the cold face folds to support the blanket in place when the module is installed. The support rods which penetrate the blanket layers also extend through the suspension tabs of a slide channel member which has a C-shaped cross-sectional configuration. The C-shaped slide channel slidingly engages a complimentary attachment member previously attached to the inner surface of the furnace.
U.S. Pat. No. 4,120,641 to Myles discloses a ceramic fiber module adapted to be welded to the furnace wall by use of a spherical attachment. The welding is performed from the inner or hot face surface of the module by reaching through the layers of ceramic fiber mats.
U.S. Pat. No. 4,287,839 to Severin et al. describes an insulating apparatus comprising blocks of insulation mat folded in corrugated manner which are penetrated below the extreme ends of the folds by carrying bars which are affixed to lugs that inturn are joined to a base plate having on opposite sides webs bent outwardly. These webs are provided with holes for the purpose of joining adjacent insulating blocks by bolts. The holding bars are affixed to the furnace wall or other support members by means of hooks.
U.S. Pat. No. 4,493,176 to Cimochowski discloses mounting means for thermal insulation modules which includes a rounded member adapted to fit into and cooperate with a C-shaped channel member attached to the insulation module. The rounded member itself is secured by a securing member to the wall of a furnace or like device. The mounting member allows the insulation module to be easily secured to the wall in sliding engagement even in locations of limited access.
U.S. Pat. No. 4,578,918 to Yost et al. discloses a means for securing fiber blanket insulation and modules to furnace walls comprising a pin attached to the wall of the furnace with an elongated aperture near its outer end through which extends a second rod of rectangular cross section the rod including a crimped mid-section. The crimped section and aperture are formed such that the rod can be inserted through the aperture to the crimp and then rotated ninety degrees to lock the retaining rod in position. The retaining rod penetrates substantially perpendicularly through the layers of ceramic fiber blanket.
U.S. Pat. No. 3,687,093 to Byrd, Jr., discloses a furnace lining which is anchored by a tubular ceramic anchor and a metal bushing fitted therein secured by welding or other means to the metal wall of the furnace. The tubular anchor includes adjacent its inner end an inwardly flared portion which is engaged by the outer surface of a complementary configured metal bushing. Access to the furnace for welding is provided via the opening in the tubular ceramic anchor Following installation the bore of the anchor is plugged with suitable ceramic refractory.
U.S. Pat. No. 3,742,670 to Byrd, Jr., discloses a thermal insulation construction in which a stud member is welded onto the furnace shell, insulation lining is placed over the projecting stud, and the hot end of the stud is protected by a refractory protector of cup-like shape retained by a holding nut. The cup is filled with cast refractory mixture sufficient to completely fill the cap and cover the holding nut and end of the stud.
U.S. Pat. No. 4,379,382 to Sauder discloses an insulation module which carries a fastener actuated by introducing a tool through the hot face of the module, or a fastener introduced into the module and actuated through the hot face at the time of module installation. Of particular note are FIGS. 2 and 6. The fastener may be a weld on type such as that disclosed in U.S. Pat. No. 3,706,870 or a screw or bolt. A stud gun such as that disclosed in U.S. Pat. No. 4,032,742 may be inserted into the hot face of the module to engage the stud assembly and thereafter tighten a nut onto the threaded stud. The fastener may carry a removable sleeve portion covering the nut which is manually removed from the stud assembly through the hot face of the module following attachment.
U.S. Pat. No. 4,478,022 discloses an insulation attachment system similar to that described in regard to U.S. Pat. No. 4,578,918 except that the insulation lock retaining pins are notched mid way thereof to cooperate with an aperture in the end of this previously welded stud. The retaining pin is passed through the aperture of the stud and rotated to provide an interlock with the notched portion of the pin with the aperture of the stud.
U.S. Pat. No. 4,516,374 to Finney discloses a ceramic fiber blanket insulation module which is secured to the furnace wall by a pair of retainer bar supports each having first and second ends with the first end being adapted to be secured to a furnace wall at spaced apart locations, an elongated retainer bar which is adapted to extend laterally through the module and engage with the free ends of the retainer bar supports. The modules are held in generally trapezoidal configuration by a protective cover which facilitates installation by facilitating access to the previously installed retainer bar mounting brackets.
U.S. Pat. Nos. 3,819,468; 3,993,273; and 4,574,995 to Sauder et al. discloses a ceramic fiber insulation module which may be attached to the furnace wall through use of a stud welding gun inserted through the exposed hot face of the module.
Advertising literature of unknown date published by Babcock and Wilcox, describes ceramic fiber insulation modules identified as Saber Bloc.RTM., Saber Bloc.RTM. II, Kao-Bloc, Saber Sections.RTM. and Uni-Bloc and Pyro Bloc.RTM. module. The Pyro Bloctm "Y" module includes a U-shaped yoke assembly having at the end of each leg thereof an aperture for receipt of a retaining rod which passes through the ceramic fiber insulation. The central or bottom portion of the yoke includes an aperture for receipt of a threaded fastener which is pre-affixed to a torque tube which extends to the hot face of the module.
U.S. Pat. No. 4,494,295 to Herring discloses a method for attaching refractory ceramic fiber modules to steel furnace shells. Metal brackets are welded to the furnace wall. A loop on the free end of each bracket receives pointed steel rods which impale the modules to secure them to the furnace wall.
U.S. Pat. No. 4,549,382 to Byrd, Jr., discloses a ceramic fiber blanket insulation module and a structure for attaching the module to the surface of a furnace. The attaching structure includes a suspension arm member for receiving a support rod which passes through the layers of ceramic fiber blanket. A locking lug structure is provided for locking the suspension arm member to the mounting structure while providing perceptible indication to the installer that positive locking engagement has been obtained by sliding motion of the hardware which is a part of the module relative to that hardware previously attached to the furnace wall in conventional manner, i e., by bolts or welding.
Other examples of modular ceramic fiber insulation include U.S. Pat. Nos. 3,819,468 to Sauder et al.; U.S. Pat. No. 3,854,262 to Brady; U.S. Pat. No. 3,892,396 to Monaghan; U.S. Pat. No. 4,001,996 to Byrd, Jr.,; U.S. Pat. No. 4,055,926 to Byrd, Jr.,; U.S. Pat. No. 4,086,737 to Byrd, Jr.,; U.S. Pat. No. 4,103,469 to Byrd, Jr.,; U.S. Pat. No. 4,123,886 to Byrd, Jr.,; U.S. Pat. No. 4,218,962 to Cunningham et al.; U.S. Pat. No. 4,574,995 to Sauder et al.; U.S. Pat. No. 4,429,504 to Hounsel et al.